Recent declines in oil prices and the failure of start-up biofuel processes to meet production cost targets have increased the interest in producing value added chemicals from biomass as coproducts. The vision is that these products can leverage the production of fuel by providing revenue to supplement the lower value fuel products. Replacing fossil fuel derived chemicals with renewables is itself a societal goal. Early in the biomass utilization effort, organic acids derived from sugars or cellulose decomposition were identified as attractive target molecules.

A marketsandmarkets.com study estimated the market for renewable derived organic acids will grow to 9.29 Billion USD by 2021. However, the long term market potential is much greater. Recent efforts have led to significant commercial advances. However, scaling renewable organic acids to a level where they significantly impact overall carbon use provides significant technical and non-technical opportunities and challenges.

Organic acids are of interest because there is an existing market for large quantities for use in foods, beverages and chemicals. Acetic acid, citric acid, formic acid, lactic acid, propionic acid, and fumaric acid are currently the highest volume products. A significant portion of acetic, lactic and itaconic acids are already produced from renewable sources. It is possible that renewable materials can entirely replace petroleum derived organic acids if costs could be lowered and integrated large scale processes developed. Replacing petrochemical carbon sources is of interest to environmental conscious suppliers and consumers.

The market for renewable organics acids is also driven by the stringent environmental regulations imposed by regulatory bodies of various nations on conventional organic acid producers. Organic acids can serve as platform chemicals for the production of polymers, food, coatings, lubricating oils, pharmaceuticals, cosmetics, solvents and other materials. While food and beverages remain the major markets, various organic acids that are being used in the above mentioned applications include fumaric acid, acrylic acid, lactic acid, succinic acid, acetic acid, adipic acid and others.

A number of the major players in the renewable organic development efforts are shown in Table 1. Many major chemical companies are investing in smaller start-ups to develop commercial products. This is a long term strategic investment plan aimed at protecting their business as against a return to high oil prices and increased pressure from governments and environmental motivated consumers. A number of governments, particularly in Europe and the U.S., have been promoting the research and development efforts with funding and regulatory efforts.

Organic acid markets are highly competitive and very price sensitive. It is difficult for the renewable materials prepared using extraction and/or advanced fermentation technology to compete given the current costs of petroleum derived starting materials. Major efforts to commercialize these sugars for use as a starting material for other materials that began during the era of high prices are currently reaching the commercial stage.

Renewable lactic acid is already being used to produce a polymer PLA which is the preferred plastic for 3D printing. Commercial production of 2,5-Furandicarboxylic acid for use in making PFT as a replacement for PET is planned by DuPont and ADM. Production of succinic acid on a commercial scale is planned. If oil prices return to high levels there are a number of renewable products derived from adipic acid could be produced at lower costs than non-renewable products.

Significant advances in technology are needed to make renewable organic acids and derived products cost competitive with their petroleum analogs. There continues to be significant investment in developing new organisms and enzymes that produce higher yields of targeted acids. Of particular interest are microbes that can resist poisoning by higher concentrations of acid.

The ability to produce higher concentrations of a specific product addresses one of the major limitations of the renewable production, product separation, and purification. Many of the applications require high purity materials. The cost of separation and purification can be 2/3 of the overall production costs of the acids.

As long as refined sugars are the major source of carbon it will be difficult to lower costs. There are also concerns of the sustainability of renewable sugars derived from sources currently used for food. Logistics are also a major issue including both transportation and dealing with seasonal supply variations. Continued progress towards economical production of fermentation feeds from lignocellulose could help alleviate this conflict. However, the impurities in the cellulose derived from this approach may limit the use of some promising strains of microbes.

Processes for downstream conversion and the upgrading of the renewable acids to commercially acceptable materials are needed. These include integrating the biological synthesis and chemical processes on a commodity scale. There are a few examples where this has been demonstrated to date. Scale up is also a major issue. Fermentation processes are generally run at smaller scales than chemical conversion process. There are also difficulties starting and stopping processes as dictated by product demand and feedstock availability.

There are also significant non-technical barriers. Public perceptions of genetic modification and biotechnology needs to be improved. The products derived from these processes need to be accepted as natural and green. Implementation of green content guidelines and regulations would help. Creative methods for financing projects need to be developed including private/public partnerships and incentives are needed. However, the basics of product marketing still apply. Replacing long established production chains with drop-in products will be difficult to do economically. The best incentives will be to produce products with superior properties at attractive prices.

In the long term, it is clear that renewable organic acids will play an important role in the effort to better use biomass as source of fuel and chemicals. Getting to this point will be a very complex project. It will require collaboration between a variety of experts knowledgeable in both the biological and chemical process along with financing, scale-up, production and regulation. Lee Enterprises can help with our large group of experienced consultants who help developers take advantage of the available opportunities. We are available and ready to provide assistance.

About the Author

Lorenz earned a degree in Chemistry from the University of Pennsylvania and a Ph.D. from Washington University in St. Louis. He is the inventor on more than 20 US patents with 8 more pending and 15 technical papers He has a unique blend of process, catalyst and characterization skills in both hydrocarbon, carbohydrates and lignin materials. He had 26 years’ experience at UOP, the premier licensor of refining and petrochemical catalysts and processes. While at, a biofuel start-up, his team successfully upgraded about 1 million gallons of catalytic pyrolysis oil to a drop in fuel that was directly blended with commercial fuels and sold to consumers.

His ideas increased yields by 10% and saved millions of dollars in capital equipment. He is an expert in catalyst preparation and applications for both direct conversion, liquefaction and upgrading. He participated in the commercialization and scale up of new technologies for Catalytic Pyrolysis, Upgrading non-traditional Feeds, Contaminant Removal, Hydroprocessing and Hydrocracking Catalysts, Heavy Oil and Hazardous Waste Recycling. He is a Six Sigma Black Belt and an expert statistical analysis, data mining, experimental design and modeling.